Thought I’d share with you this little mod that you may find helpful. Where I live, in the South, we are “blessed” with this pesky wasp called Mud Daubers which love to make their mud nest in places like your hot water and refrigerator vents. When I looked into what already made vent screens cost I said to myself that's ridicules I can make these screens for a whole lot less and did. To do this project all you have to do is get some small tie wraps and small screen 1/8” squares or less hardware cloth at your local hardware store and a pair of straight tin shears. Make a pattern with cardboard then cut the screens out for the vents and install with the tie wraps. I used Gorilla tape to attach the screens to the vents on the water heater along with some tie wraps. The only place I bought manufactured screens for this purpose was at the furnace vents.